Funny thing about these machines is they never show them with any people, so you can't tell how big they are. The first one (Sojourner)) was about as big as a shoe box and weighed about 20 pounds. The second ones (Spirit and Opportunity) were the size of a coffee table and weighed 400 pounds. This one, the third generation, is the size of a small car and weighs a ton (2,000 pounds). All you metricons divide those numbers by 2 to get your kilos.
Wheels from the three generations of Mars Rovers.
I looked but could not find a good set of dimensions. Typical populizers, all the flash and none of the facts.